Refrigerating apparatus and method



April 19, 1932. RANDEL 1,854,223

REFRIGERATING APPARATUS AND METHOD Filed Sept. 24, 1928 INVENTOR. 50m19402222:

' ATTORNEYS.

I Patented Apr. 19, 1932 UNITED STATES PATENT OFFICE I 30 FOLKE RANDEL,SAN DIEGO, CALIFORNIA, ASSIGNOR TO G. A. DUNHAM COMPANY,

, OF MARSHALLTOWN, IOWA, A CORPORATION OF IOWA REERIGERATINGAPIE'ARA'IUS AN D METHOD Application filed September; 24, 1928. SerialNo. 307,979;

My invention relates to refrigerating apparatus and the objects. thereofare: Firsh'ito provide a refrigerating apparatus whiphjis adapted tooperate under a relatively 10W pressure; second, to provide a process inwhich refrigeration is brought about by the actionof an inert gas on arich solution of gas in liquid whereby the latter is weakened causing anabsorption of heat and consequent refrigeration within portions of theapparatus; third, to provide a process of this class in whichcirculation within the apparatus is maintained by the creation of'adifferential of pressure by means of a fluid pump; fourth, to provide aprocess of this class in which a primary and tertiary medium havinggreat aflinit for each other are associated with a secon ary inertmedium adapted to cause disassociation of said primary and tertiarymedium under conditions of great temperature reduction; fifth, toprovide an apparatus of this class in which a rich solution of a primaryand tertiary medium may be readil weakened by a certain action of a 25secon ary, relatively inert medium causing a- -reduction in temperatureto said solution; sixth, to provide a process of refrigeration in whichthe various mediums employed are not in any way altered in form duringthe process, such as changing from gas to liquid form and vice versa butretain their initial form throughout the entire process, except suchaltering as is due to the solution of a vapor in a liquid, and seventh,to provide a process and apparatus of this class which are simple,conservative in space requirement, self contained and economical of oeration. I With these and other 0 jects in view as will appearhereinafter, my invention con sists of certain novel features ofconstruction, combination and arrangement of parts and portions as willbe hereinafter describedin detail and particularly set forth in theappended claims, reference being had to the accompanying drawings and tothe characters of reference thereon which form a part of thisapplication in which:

Figure 1- isa diagrammatical view of the apparatus employed in myrefrigerating sys- 5'0 tem showing certain parts and portions in sectionand other parts broken away'in order to more clearly illustrate theinvention, and

2 is a sectional view through 2 -21 of' 1g. 1. Y I

Similar characters of reference refer to similar parts and portionsthroughout-the several views of the drawings.

The evaporator 1, refrigerating element 2, absorber 3, diffusion element4, cooling jacket 5, vapor control valves 6, and 6a,'liquid controlvalves 7, and 7 a, vacuum chamber 8, circulating pump 9, motor 10,pressure chamber 11, transfer pump 12, and refrigerator 13, constitutethe principal parts and portions of my refrigerating apparatus.

The evaporator 1, communicates through the refrigerating element 2 andpipe 2a with a vacuum chamber 8. The flow of liquid from'therefrigerating element 2 to the vacu. umchamber 8, is controlled by theliquid. control valve 7. The pressure chamber 11 connects with theevaporator 1,- through pipe 11a, terminatin in a perforated element 11?)shown best in fig. 2, allowin a gas to issue and bubble through theliqui in evaporator w 1. Through the pipe 1a, gas or vapor from theevaporator 1 is ledto the diffuson element 4. This diffusion elementwhich may be made in the form of a straight tube as shown or may be madein a spiral shape or any other suitable shape to provide necessarylength to accomplish its purpose, is made of a porous material soconstituted as to permit rapid diffusion of a light gas through itswalls, but retardingand partially preventing the diffusion ofa heavy gastherethrough. A mixture of gases of different densities passing throughthis diffusion element may therefore be partially separated into itsdifferent parts, the lighter gas diffusing through its walls to theoutsidg while the heavier. gas will pass through theinside of theelement to the discharge end.

The diffusion element 4 is in communication through pipe 4a with thevacuum chamber 8, thewflow of gas to said chamber being controlled byvapor control valve 6. The evaporator lis also in communication throughthe pipe 3a with absorber 3 permitting liquid to flow from said absorberto said y is obvious that this pump 12 may be omitted except forthis-purpose. The pressure chamber 11 communicates by pipe 110 with theabsorber. Said absorber is fitted with a perforated plate or screen 30;,permitting any liquid coming from the pressure chamber to break up in afine spra during the descent through the absorber t us more readilabsorbing any absorbable vapors in sai absorber. Thepressure chamber 11also communicates at 11d with circulating pump 9, driven by motor 10 orany other suitable motive power. The discharge from this circulatingpump 9 leads into the vacuum chamber 8, into eductor nozzles 8a andfinally discharging inpressure chamber 11 at 116. As the pressurechamber is partly filled with liquid, the action of the circulating pump9 forcing liquid through eductor nozzles 8a, will cause a lowering ofthe pressure in the vacuum chamber 8, and by the exhaustin of liquid andvapors from this vacuum cham er, adding same to content in pressurechamber 11, will at the same time cause an increase of the pressure inthe pressure chamber.

It is this difference of pressure in the vacuum and pressure chamberscaused by the action in the eductor nozzles, which creates a generalcirculation of the mediums through the apparatus. The pressuredifference will be equal to the height of liquid column H in theevaporator 1. Any further increase of pressure in the pressure chamberwill cause vapors to flow through 11a to 11b,,bubbling up through theliquid in the evaporator 1. This flow is also controlled by controlvalve 7a. Itbeing noted that the pressure difference will cause ageneral circulation of liquid from the evaporator 1 down through therefrigerating element 2 into the vacuum chamber 8, raising the level 15of the liquid in the pressure chamber 11, causing a further flow ofliquid from the pressure chamber 11, through the pipe 110 to theabsorber 3, the height H from the level 15 to the inlet of the absorberbeing the same as the height H in the evaporator 1. This flow iscontrolled by the valve Get. By controlling the flow by valves 6a and7a, the height H may be varied in the absorber and evaporator, and neednot be the same in these two elements. From the absorber the liquid willflow by gravity or by means of the pressure pump 12, back to theevaporator 1. There will also be created a general circulation of gasesor vapors from the evaporator 1 through the pipe 10:, to the diifusionelement 1, thence through same and through the pipe 4a to the vacuumchamber 8, thence to the pressure, chamber 11 and through the pipe 11aback to the evaporator 1, bubbling through any liquid contained in saidevaporator.

The absorber 3 is surrounded by the cooling jacket 5, containing coolingwater, entering at 5a and discharging at. 56. The absorber may also beconstructed so as to permit air cooling.

My process of refrigeration is based upon the following,

- First: The fact that a gas in solution in a liquid may be removed fromthis liquid by bubbling a foreign gas through the solution, providedthat this foreign as is chemicallyinert to the first mentione gas and tothe liquid.

Second: That ent densities may be separated by permitting the lightergas to difiuse through porous membranes.

Third: That certain gases in being absorbed in liquids will generateheat, and conversely, when again separated from the liquid heat will beabsorbed.

In carrying out the process of refrigeration within my apparatus, Iemploy three or more mediums which 1 preferably refer to as primaryorrefrigerating-medium, and second and tertiary supplementary mediums. Theprimary medium is a fluid which under normal conditions remains in vaporform and which as will be shown later, remains in this form during theprocess of refrigeration in a mixture of gases of difiermy apparatusexcept as to such change in v form as accompanies an absorption in aliquid. The tertiary is a fluid which under normal conditions remains aliquid and as will also be hereinafter shown, remains in this formduring the process of refrigeration in my apparatus. The tertiary mediumhas a strong afiinity for the primary medium absorbing same andgenerating heat during .this action. The secondary medium employedhowever, is ractically inert in respect to both the prlmary and tertiarymediums. The secondary medium is in the form of a gas and remains inthis form during the entire process of refrigeration.

As suitable primary mediums may be mentioned, ammonia, sulphur dioxide,hydrogen chloride. As secondary mediums: hydrogen, nitrogen, air, carbondioxide, butane gas or other hydro-carbon gas, etc., and'as tertiarymedium: water, alcohol, ether, water with calcium-chloride, water withpotassiumcarbonate, etc. While certain mediums have thus been mentioned,T do not wish to be lim-. ited to the use of such mediums as it isobvious that many others are also well suited for the purpose as myapparatus will operate with any combination of mediums having in generalthe same characteristics as the ones mentioned.

For the purpose of explaining the action taking place during the processof refrigeration within the apparatus, it will be assumed that theprimary medium employed is ammonia vapor; second medium is nitrogen,

and the tertiary medium is water with calcium-chloride in solution, thecalcium-chloride being introduced to prevent freezing of water. Thesystem is charged with the three mediums (not considering the fourth,calcium-chloride), so that water in the bottom of the absorber 3 and inthe evaporator is highly charged with ammonia gas, so called strongliquor, and water in the pressure chamber 11 is sli htly charged withammonia gas, or 'so called weak liquor. Also the vapor above the liquidlevels is mainly nitrogen gas. Now when; the circulating pumpis started,pressure will increase in the pressure chamber 11 and a generalcirculation of liquid and vapors will; occur as described above. whilebubbling through the strong liquor-in the evaporator will cause theammonia gas to evaporate and mix with the nitrogen gas. The temperatureof the rich liquor will be lowered, and heat will be absorbed from thesurrounding refrigerator.

As the liquor flows downwardly in. the opposite direction to ,thebubbles it becomes weaker and weaker and will absorb more and more heat.The flow is controlled bythe control valve 7 so as to allow-sufficienttime for nearly all the ammoniato be driven out, so that the liquorpassing through the refrigerating element is mainly water. The mixedgases will pass to the difi'usion element 4.

7 There, the light ammonia gas will pass quickly through the walls,while the nitrogen will passto t e vacuum .chamber8. The length 4 of thetravel throu h this diffusion element is adjusted so as to ree themixture of practically all the ammonia gas, before the end of gaswilloccur.

of this diffusion element.

the element is reached.

The weak liquor in the pressure chamber 11 will be forced up through thepipe 110 and into absorber 3. In descending through this absorber, thenow cool and.weak liquorbeing in good condition to reabso rb ammonia gaswill absorb this gas which has diffused through the walls of thediffusion element,

.and will cause a still more rapid flow of ammonia gas through the wallsby creating a pressure difference as far as this ammonia gas concernsbetween the outside. and inside Nitrogen gas, being practicallyinsoluble in wa ter,'no such pressure difference will occur as far'asthis nitrogen gas is concerned, and once an equal pressure. on thisnitrogen gas has been established inside and outside the diffusionelement, no further diffusion of the nitrogen Any ammonia gigs notdiffused through to absorbed in being mixed Nitrogen with weak liquor inthe vacuum chamber 8 and the pressure-chamber 11.

When ammonia gas is reabsorbed in the absorber 3, heat will begenerated, which heat is removed by cooling water or by atmosphere asdesired, and the same amount of heat which is thus generated and removedfrom the absorber, will later be absorbed in the evaporator, causingrefrigeration.

It should be noted that while the motive power in a mechanical sense ismuch smaller in my process than in any other, being only the small powernecessary to cause circulation against very small pressure difference,the motive power from a thermodynamic sense is practically the same. Therefrigcrating efiect of any system is dependent upon theremoval of heatin a condenser from a medium, which is changed from vapor form to liquidform. By my process a somewhat similar transfer of heat occurs in an.absorber, and a gas is going through an action of being considerablyreduced in volume by being absorbed in a liquid. The difference betweenmy process and older processes is the fact that high pressure is notrequired to cause'this reduction of volume. It should also be noted thatmy apparatus is constructed ac- I cording to counter flow principles,the mediums which are separated orcombined in the absorber andevaporator flowing in opposite directions, thus increasing theefl'ectiveness of the apparatus.

Though I have described a particular apparatus and agents for obtainingrefrigeration, I do not wish to be limited to this par ticular apparatusand these agents, but desire to include within the scope of my inventionthe apparatus and agents as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a refrigerating apparatus, a circulating system containing asolution of a soluble gas in a. liquid, and a relatively inert gas, saidtion of heat and consequent refrigerating action, means for causingmixlng'of said inert gas with said soluble gas after said separation hastaken place and further means for causing a partial separation of thesaid soluble. gas from the said inert gas by permitting the lighter, gasto diffuse through a diffusion member at a greater velocity than theheavier gas, and means for again absorbing the soluble-gas in theliquid. I

2. A process of refrigeration consisting in bubbling a relatively inertgas through a solution of a liquidand a soluble gas so as to cause therelease of a portion of the soluble gas, uti

lizingthe weakened solution to absorb heat in a refrigerating coil,separating'the released soluble gas from the inert gas by diffusing thesoluble gas through a diffusion member reabsorbing the solu le gas inthe weakene solution, and dissipating the heat thus released.

3. In an absorption refrigerating process, the step of passing a mixtureof soluble and inert gases through a porous receptacle from which thesoluble gas will diffuse at a greater rate than the inert gas, andpassing a liquid about the porous receptacle whereby the soluble gaswill be absorbed in theliquid.

4. In an absorption refrigerating process, the step of passing a mixtureof soluble and inert gases in one direction through a porousreceptaclefrom which the soluble gas will diffuse at a greater rate than the inertgas, and passing a liquid in the opposite. direction about thereceptacle whereby the soluble gas will be absorbedin the liquid.

5. An absorption refrigerating process in v which a liquid ismechanically forced to circulate from a pressure chamber through anexhausting chamber and thence back to the pressure chamber thus causingthree other fluid circulations as followsza circulation of a portionofthe liquid from the pressurechamber through an absorption space, an

" evaporation space, a refrigerating space, the

exhausting chamber and back to the pressure chamber, a circulation ofinert gas from the pressure chamber through the evaporation space, theabsorptionspace, the exhausting chamber and back to the pressurechamber, and acirculation of soluble gas from the evaporation space withthe inert, gas to the absorption space, thence in solution in the liquidback to the evaporation space.

6. In an absorption refrigerating apparatus, an absorber comprlsing anouter receptacle, means for conducting'a liquid into the means forcirculating a heat-removing fluid through the outer receptacle, meansfor conducting a liquid into the upper portion of the intermediatereceptacle and removing the liquid from the lower portion of theintermediate receptacle, means-for conducting a mixture of inert andsoluble gases into the lower portion of the porous receptacle, and meansfor withdrawing the inert gas from the upper portion of the porousreceptacle.

8. A refrigerating apparatus comprising a jet exhauster and a pressurechamber, means for circulating a liquid from the pressure chamberthrough the jet exhauster and back to the pressure chamber, anevaporator, a refrigerating coil, an absorber, means comprising theexhauster for circulating a liquid from the pressure chamber through theabsorber, the evaporator and the refrigerating coil back to the pressurechamber, and means also including the exhauster for circulating an inertgas from the pressure chamber through the evaporator, and the absorberback tothe pressure chamber, said latter means also including a conduitthrough which a soluble gas is conveyed along with the inert gas fromthe evaporator to the absorber.

9. A refrigerating. apparatus comprising a jet exhauster and a pressurechamber, means for circulating a liquid from the pressure chamberthrough the jet exhauster and back to the pressure chamberfanevaporator, a refrigerating coil,'an absorber comprising an inner porouschamber and an outer non-porous ciamber, in which the inner chamber isenclosed, means comprising the exhauster for circulating a liquid fromthe pressure chamber through the outer chamber of the absorber, theevaporator and the refrigerating coil back to the pressure chamber, andmeans also including the exhauster for circulating an inert gas from thepressure chamber through the evaporator and the inner porous chamber ofthe absorber'back to the pressure chamber, said latter means alsoincluding a conduit through which a soluble gas is conveyed along withthe inert gas from the evaporator into the porous chamber.

10. A refrigeratlng apparatus comprising a jet exhauster and a pressurechamber, means for circulating a liquid from the pressure chamberthrough the jet exhauster and back to the pressure chamber, anevaporator, a refrigerating coil, an absorber comprising an inner porouschamber and an outer non-- porous chamber in which the inner chamber isenclosed,means for dissipating heatfrorn the outer chamber, meanscomprising the exhauster for circulating a liquid from the pressurechamber through the outer chamber of the absorber, the evaporator andthe re- .1 frig'erating coil back to the pressure chamber,

and means also including the exhauster for circulating an. inert gasfrom the pressure chamber through the evaporator and the inner porouschamber of-the absorber back to the pressure chamber, said latter meansalso including a conduit through which a soluble gas is conveyed alongwith the inert gas from the evaporator into the porous chamber. j

11. A refrigerating apparatus comprising a suction chamber and apressure chamber, means for circulating fluids between these chambers tomaintain a pressure difference therebetween, an evaporator, a refricrating coil, an absorber, conduits for one atmg a liquid from thepressure chamber through the absorber, the evaporator, and therefrigerating coil to the suction chamber, and conduits for circulatingan inert gas from the pressure chamber through the evaporator and theabsorber to the suction chamber, said latter conduits including aconduit through which a soluble gas is conveyed along with" the inertgas from the evaporator to the absorber.

12: A refrigerating apparatus comprising a suction chamber and apressure chamber, means for circulating fluids between these chambers tomaintain a pressure difierence therebetween, an evaporator, arefrigerating coil, an absorber comprising an inner porous chamber an anouter non-porous amher in which the-inner chamber is enclosed,

conduits through which a liquid is circulated from the pressure chamberthrough the outer chamber ofthe absorber, the evaporator and therefrigerating coil to the suction chamber, conduits through which aninert gas is circulated from the pressure chamber through the evaporatorand the porous chamber of the absorber to the suction chamber, saidlatter conduits including a conduit through which a soluble gas isconveyed along with the inert gas from the evaporator into the porouschamber.

13. A refrigerating apparatus comprising a suction chamber and apressure chamber, a means for c1rculat1ng fluids between these chambersto maintain a pressure difference therebetween, an evaporator, arefrigerating C011, an absorber comprising an inner porous chamber andan outer non-porous chamber m "which the inner chamber is enclosed,means for dissipating heat from the outer chamber,

.. conduits through. which a liquid is circulated from the'pressurechamber through the outer chamber of the absorber, the evaporator andthe refrigerating coil to the suction chamber, conduits through which aninert gas is circulated from the pressure chamber through theevapbratorand the porous chamber of the absorber to, the suctionchamber, said latter conduits including a conduit through which asoluble gas is conveyed along with the inert gas from the evaporatorinto the porous chamber. y

In testimony whereof, I have hereunto set my hand at San Diego,California, this 17th day of September, 1928:

. I BO FOLKE RANDEL,

